Time for a new battery. They are consumable and eventually, after so many cycles, they're unreliable because of the diminished capacity. Since power draw is inconsistent, sometimes a low capacity battery will last minutes, sometimes longer. At that low of a capacity, it's not going to be worth using.

Liquid and computers don't mix. It might seem simple, but we see an incredible amount of people post here about spills. Keep drinks and other liquids away from your expensive electronics!